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8Sci CH2
8th Science CH2 Magnetism
Term | Definition |
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electric generator | produces electricity for home and business use by inducing currents through rotating a coil within a magnetic field; in the US household alternating current changes direction 120 times/second |
electric motor | motor that uses an electromagnet to change electric energy into mechanical energy, creating the ability of machines such as washers and vacuum cleaners to perform work |
electromagnet | magnet produced by passing an electric current through a coil of wire wound around a core |
induced current | electric current produced by using a magnet; results when a magnetic field is changed in a coil-the field can be changed by moving either the coil or the magnet |
induced magnetism | magnetism that occurs only in the presence of a magnetic field-when the magnetized object is removed from the magnetic field, its poles soon disappear |
loudspeaker | changes variations in electric current into sound waves in radios and speakers |
magnetic field | three-dimensional region where magnetic forces act; Earth;s huge magnetic field, which resembles a large bar magnet, extends far out into space and protects us from showers of high-energy charged particles |
magnetic poles | in a bar magnet, the two ends that point north-south--the places where the magnetic field is strongest; two north-seeking poles repel each other, but a north-seeking pole and a south-seeking pole attract each other |
transformer | ensures that electricity produced by a power company has the correct voltage by raising (step-up transformer) or lowering (step-down transformer) the voltage to the needed level |